The primary objective of this study is to evaluate the efficacy and safety of cyclophosphamide and bevacizumab in combination with Envafolimab in the treatment of recurrent epithelial ovarian cancer (EOC), fallopian tube cancer, and primary peritoneal cancer.

Inclusion Criteria:

• Age 18-70 years Histologically or pathologically confirmed epithelial ovarian cancer (EOC), fallopian tube cancer, primary peritoneal cancer Patients with recurrent ovarian, fallopian tube, and primary peritoneal cancer following platinum-based chemotherapy measurable lesions (according to RECIST 1.1 criteria, non-lymph node lesions CT scan long diameter ≥ 10 mm, lymph node lesions CT scan short diameter ≥ 15 mm) ECOG PS score: 0 - 1;

Exclusion Criteria:

• Subject has prior or concurrent other malignancy Prior treatment with other PD-L1/PD-L1 inhibitors cannot be enrolled; Subject has known previous hypersensitivity to macromolecular protein preparations or applied drug components

epithelial ovarian cancer (EOC), fallopian tube cancer, primary peritoneal cancer